Distribution of emm type and antibiotic susceptibility of group A streptococci causing invasive and noninvasive disease.
To determine the prevalence of macrolide antibiotic and levofloxacin resistance in infections with Streptococcus pyogenes (group A streptococcus or GAS), strains were collected from 45 medical institutions in various parts of Japan between October 2003 and September 2006. Four hundred and eighty-two strains from patients with GAS infections were characterized genetically. Strains were classified into four groups according to the type of infection: invasive infections (n=74) including sepsis, cellulitis and toxic-shock-like syndrome; acute otitis media (AOM; n=23); abscess (n=53); and pharyngotonsillitis (n=332). Among all strains, 32 emm types were identified; emm1 was significantly more common in invasive infections (39.2 %) and AOM (43.5 %) than in abscesses (3.8 %) or pharyngotonsillitis (10.2 %). emm12 and emm4 each accounted for 23.5 % of pharyngotonsillitis cases. Susceptibility of GAS strains to eight beta-lactam agents was excellent, with MICs of 0.0005-0.063 mug ml(-1). Macrolide-resistant strains accounted for 16.2 % of all strains, while the percentages of strains possessing the resistance genes erm(A), erm(B) and mef(A) were 2.5 %, 6.2 % and 7.5 %, respectively. Although no strains with high resistance to levofloxacin were found, strains with an MIC of 2-4 mug ml(-1) (17.4 %) had amino acid substitutions at either Ser-79 or Asp-83 in ParC. These levofloxacin-intermediately resistant strains included 16 emm types, but macrolide-resistant strains were more likely than others to represent certain emm types.
Wajima
Takeaki
T
Laboratory of Molecular Epidemiology for Infectious Agents, Graduate School of Infection Control Sciences, Kitasato University, Tokyo, Japan.
Murayama
Somay Y
SY
Laboratory of Molecular Epidemiology for Infectious Agents, Graduate School of Infection Control Sciences, Kitasato University, Tokyo, Japan.
Sunaoshi
Katsuhiko
K
Laboratory of Molecular Epidemiology for Infectious Agents, Graduate School of Infection Control Sciences, Kitasato University, Tokyo, Japan.
Nakayama
Eiichi
E
Laboratory of Molecular Epidemiology for Infectious Agents, Graduate School of Infection Control Sciences, Kitasato University, Tokyo, Japan.
Sunakawa
Keisuke
K
Laboratory of Infectious Disease, Graduate School of Infection Control Sciences, Kitasato University, Tokyo, Japan.
Ubukata
Kimiko
K
Laboratory of Molecular Epidemiology for Infectious Agents, Graduate School of Infection Control Sciences, Kitasato University, Tokyo, Japan.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000942:Antigens, Bacterial / Q000145:classification / Q000235:genetics*; D001425:Bacterial Outer Membrane Proteins / Q000145:classification / Q000235:genetics*; D002352:Carrier Proteins / Q000145:classification / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D064704:Levofloxacin; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009154:Mutation; D015242:Ofloxacin / Q000494:pharmacology; D013290:Streptococcal Infections / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000187:drug effects* / Q000235:genetics
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; C014689:streptococcal M protein; D064704:Levofloxacin; D015242:Ofloxacin